Migrating to SIP

ISDN lines have served businesses well over the years, but times are changing. BT have announced that that by 2025 they aim to completely phase out ISDN and PSTN services in favour of IP. If your business is still working with ISDN, then it’s time to speak to a trusted SIP Provider to explore your options.

SIP is a flexible alternative that provides various telecom benefits for businesses. Below we’ve outlined how your business can plan ahead for this change:

Identify Existing Requirements

The first step of any SIP migration process involves mapping out your existing phone network. By considering how many phone numbers you have, user extensions, business processes and more, your SIP provider can map out a detailed plan to ensure the migration caters to your needs.

Change is Good

Do you currently pay too much for ISDN? Are your lines tied to one physical location? Does your system fail under high volumes of calls?

If this sounds familiar, then your business is ready for a change! Upgrading to SIP is a great excuse to eliminate any frustrations within your existing system. Once you’ve mapped out your phone network as above, make note of any communication ‘pain points’ you currently have and allow SIP technology to ease your pain.

Testing Phase

When changing your network, it’s worthwhile implementing processes that will help keep activity going should anything fail to perform. Outline how calls are verified and handled throughout your business to ensure failure systems are in place. That way if anything breaks it won’t impact your business’ daily activity.

Selecting the Right Equipment

Each business is unique and has different requirements. Depending on the level of flexibility your business needs, your SIP provider can offer hardware to complement your network.

IIPPBX can initially be costly but it provides much greater functionality. If you are implementing IPPBX then you have the option of using existing analogue handsets with analogue telephone adaptors or alternatively you can replace all handsets with IP phones.

It is also important for your network to have security! Ideally your business should use a SBC to control calls or a SIP-aware firewall so that your network knows what suspicious SIP traffic looks like.

Selecting a SIP Provider

When your network requirements, testing and equipment is up to speed you need to select a SIP trunks provider. A trusted provider will have the ability to port a large volume of numbers, provide support and offer anti-fraud measures to limit your exposure should you fall victim to a hack.

Make sure you work with a provider that offers your business everything it needs at a competitive rate.


Once you’ve outlined your networks requirements it’s time to install your new hardware and configure it with your SIP phone service! Make sure to carry out a few tests here to ensure everything it running smoothly. There shouldn’t be many issues but if there is it’s best to iron these out in the beginning.


When switching to SIP networks you must submit a porting request for your numbers and provide as much information as possible. This can take up to a few weeks, but your ISDN lines can work alongside your new SIP trunks! That way the changeover remains as seamless as possible. Once your numbers are working, you can cancel your ISDN accounts and enjoy your new lines of communications.

Want to learn more?

Contact Standard Utilities today to find a solution for your business.